Reamer



Oct. 8, 1929.

c. P. ,WETMORE REAMER Original Filed June 21, 1921 IN VEN TOR.

(Z Mz 5 E Mfr/mas A TTORNEY.

Patented 0a. 8, 1929 UNITED STATES,

cnmLns r. wnrmoan, or MILWAUKEE, wrsconsm, ASSIGNOR "ro' wn'rmonn m maPATENTIF, OFFICE.

. COMPANY, OF MILWAUKEE, WISCONSIN, A CORPOIMQTIQN OF "WISCONSINBEA'lIIER- Original application filed June 21 1921, Serial No. 479,356.Divided and this application filed Ju1y2,

1924. Serial No. 723,695.

This invention relates to reamers.

It relates particularly to reamers having I t1on of rotation of thereamer head, and

removable blades.

In accordance with the invention, the reamer head is provided withgrooves within which the blades are inserted, the blades-fitting looselywithin the grooves so that they may be tilted backwardly with respect tothe direction of rotation of the reamer to cause contact between theblades and grooves at only the top and bottom of the grooves, and meansare provided for holding the blades securely in this two-point contactwith the grooves. p 1

An object of the invention is to provide a blades thereof loosely tiltedbackwardly with respect to the direction of rotation of the reamer,- sothat there is two-point contact between the grooves and blades.

Another object is to provide an improved. means for securing blades to areamer head by tilting the blades thereof backwardly within grooves inthe reamer head and holding the blades in two-point contact with thegrooves.

drawings, in which Another object is to provide an improved means forsecuring blades to a reamer head to eliminate chattering and to insuresmooth and accurate cuttin Other objects and advantages will hereinafterappear.

For the purpose of illustrating the invention, an embodiment thereof-isshown in the Figure v1 is a transverse sectional view, showing themanner in which the blades are tilted backwardly within-the grooves inthe reamer head and held in this position in twopoint contact with thegrooves;

Fig. 2 is-a perspective view of a blade;

Fig. 3 is a side elevation of the reamer,

artly in section, showing the manner in which the blades are arrangedand assembled with respect to the reamer head; and

Fig. 4 is an end view, looking toward the left in Fig. 3.

The invention comprises, in general, a reamer head 1 provided withgrooves 2,

blades 3 loosely fitted withinthe grooves and tilted backwardly withrespect to the direcmeans 4 for holding the blades in two point' contactwith the grooves. v

The means 4 for holding blades 3 in two polnt contact with grooves'2m'aycomprise screws 5. The screws 5 are threaded into the reamer head 1, asshown in Fig. 1, so that the lower ends thereof engagethe lower portionsof the blades to tilt the same backwardly'with respect to the directionof rotation of the reamer head and thereby hold the blades 1n dcozntactwith grooves 2 at two points 6 an The direction of rotation of thereamer isindicated by the arrow in Fig. 1,

-Each blade 3 is provided with a recess 8 within which the lower end ofscrew 5 fits.

The outer ends of screws 5 are provided with suitable recesses having acharacteristic shape, 'as indicated in Fig. 3, for the reception of awrench. 1

' 'The blades 3, of course, actually engage grooves 2 on two lines andnot on two points, the words two-point contact being used merely forconvenience in describing and claiming the invention.

When the reamer head is rotated in the direction of the arrow, as shownin Fig. 1,

each blade 3 will be firmly supported at the upper portion 6 of tiltedbackwardly the bottom of the blade will A only engage the bottom of thegroove at the point 7.

The improved method of holding the blades in two-point contact with thegrooves has been shown in connection with an adjustable reamer describedand claimed in my co-pending application Serial No. 479,356,

filed June 21, 1921, (Patent No. 1,621,227,

groove, a blade loosely fitted in the the bottoms of the groove and ofthe blade being shaped to provide a fulcrum between the forward edge ofthe bot-tom of the blade and the forward portion of the bottom of thegroove and to provide a clearance between the rearward portion of thebottom of the blade and the rearward portion of the bottom of thegroove, said blade being tilted backwardly in the groove about saidfulcrum until its back face has line contact with the outer edge of theback wall of the groove, the forward edge of the bottom of the bladeengaging the front wall of'the groove, and means for tilting the bladerearwardly and holding it engaged with its fulcrum and with the frontand back faces of the groove. p

2. A reamer comprising a head having a groove, a blade loosely fitted inthe groove, the bottoms of the groove and of the blade being shaped toprovide a fulcrum between the forward edge of the bottom of the bladeand the forward portion of the bottom of the groove and to provide aclearance between the rearward portion of the bottom of the blade andthe rearward portion of the bottom of the groove, said blade beingtilted backwardly in the groove about said fulcrum until its back facehas line contact with the outer edge of the back wall of the groove, theforward edge of the bottom of the blade engaging the front wall of thegroove, and a screw thread ed through the head at an angle, said bladehaving its back face provided with a notch with which the screw engages.

3.. A reamer comprising a head provided with a groove, a blade fittedloosely in the groove and fulcrumed on the bottom wall thereof, saidblade being tiltable backwardly about its fulcrum until the upperportion of its back face engages the upper-part of the back Wall of thegroove,'the lower portion of the front of the blade engaging the lowerpart of the front wall of the groove, said blade being otherwise freefrom contact with the walls of the groove, and means for tilting theblade backwardly about and holding it firmly engaged with its fulcrumand'also firmly against the parts of the front and backwalls of thegroove wlth which it 1s engaged.

4. "A reamer-comprising a head provided with a groove, a blade looselyfitted within the groove and fulcrumed near the bottom of the groove andtiltable backwardly about its fulcrum to a rearwardly inclined positionin which the lower portion of its front face and the upper portion ofits rear face have line contact only with the respectively opposed wallsof the groove, and means for clamping the blade in such rearwardlyinclined position in engagement with the fulcrum and with the groovewalls, the front and rear faces of the blade having substantially linecontact only with portions of the opposed walls of the groove with whichthey are engaged. groove,

5. A reamer comprising a head having a groove, a blade fitted loosely inthe groove, the bottom of the groove and the bottom of the bladediverging in a direction opposite to the direction of rotation of thehead whereby the forward lower corner of the blade is engaged with andfulcrumed on the bottom of the groove at the forward lower cornerthereof and the lower blade is engaged front wall of the groove whilethe upper portion of the backof the blade is engaged with the upper partof the rear wall of the groove, said blade being otherwise free fromcontact with the walls of the groove, and clamping means'coacting withthe blade for firmly holding it in position in the groove and inengagement with its fulcrum and with the front and rear walls of thegroove as aforesaid.

, 6. A reamer comprising a head provided with a groove, a blade fittedloosely in the groove, and fulcrumed near its lower front edge on thebottom wall of the groove, the front and bottom walls of the groovedefining a greater angle than the front and bottom faces of the blade,whereby said blade may be rocked on its fulcrum, and means to tilt theblade rearwardly into contact with the upper portion of the rear wall ofthe groove, and to maintain the blade on its fulcrum.

7. A reamer comprising a head provided with a groove, a blade fittedloosely in the groove, and fulcrumed near its lower front edge on thebottom wall of the groove, the frontand bottom walls of the groovedefining a greater angle than the front and bottom faces of the blade,whereby said blade may be rocked on its fulcrum, and means to tilt theblade rearwardly into contact with the upper portion of the rear wall ofthe groove,

front portion of the with the lower part of the upper portion of thefront face of the blade and the lower portion of the rear facethereofbeing out of contact with the respectively opposed portions of thegroove walls.

8; A reamer comprising a head having a groove therein, a bladepositioned in the groove, the blade having a smaller transversedimension than the groove throughout the depth of the latter, the bladeand groove being so formed as to provide a fulcrum about which the bladeis tiltable b-ackwardly with respect to the direction of rotation of thehead and also to provide an abutment with which the lower edge of theblade is engaged to limit positively the forward movement of the loweredge of the blade, and means to tilt the blade rearwardly intosubstantially line contact with the upper portion of the rear wall ofthe groove and to maintain the blade on its fulcrum, at least the upperportion of the front face of the blade and the lower portion of the rearface thereof being out of con- P tact with the respectively opposedportions of the groove Walls.

In wltness whereof I hereto aflix my signature.

- CHARLES P.WETMORE.

